Plan Your Own Party Kit is a kit for throwing fun parties. It only appears in the episode, "Party Pooper Pants."
Inside the kit contains a list of Bikini Bottomites to invite to the party, an instruction manual, and some party supplies (balloons, noise makers, etc.). The manual says that the party could go wild, but the party was dull. The store-keeper, Lou, gives it to SpongeBob for free.